1 files changed, 26 insertions, 5 deletions

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 29d8693d0c61..1bf4807cb21e 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -31,6 +31,7 @@
 #include <linux/stop_machine.h>
 #include <linux/hugetlb.h>
 #include <linux/memblock.h>
+#include <linux/bootmem.h>
 
 #include <asm/tlbflush.h>
 
@@ -1066,6 +1067,16 @@ out:
 }
 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
 
+static void reset_node_present_pages(pg_data_t *pgdat)
+{
+        struct zone *z;
+
+        for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
+                z->present_pages = 0;
+
+        pgdat->node_present_pages = 0;
+}
+
 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
 static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
 {
@@ -1096,6 +1107,21 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
         build_all_zonelists(pgdat, NULL);
         mutex_unlock(&zonelists_mutex);
 
+        /*
+         * zone->managed_pages is set to an approximate value in
+         * free_area_init_core(), which will cause
+         * /sys/device/system/node/nodeX/meminfo has wrong data.
+         * So reset it to 0 before any memory is onlined.
+         */
+        reset_node_managed_pages(pgdat);
+
+        /*
+         * When memory is hot-added, all the memory is in offline state. So
+         * clear all zones' present_pages because they will be updated in
+         * online_pages() and offline_pages().
+         */
+        reset_node_present_pages(pgdat);
+
         return pgdat;
 }
 
@@ -1912,7 +1938,6 @@ void try_offline_node(int nid)
         unsigned long start_pfn = pgdat->node_start_pfn;
         unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages;
         unsigned long pfn;
-        struct page *pgdat_page = virt_to_page(pgdat);
         int i;
 
         for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
@@ -1941,10 +1966,6 @@ void try_offline_node(int nid)
         node_set_offline(nid);
         unregister_one_node(nid);
 
-        if (!PageSlab(pgdat_page) && !PageCompound(pgdat_page))
-                /* node data is allocated from boot memory */
-                return;
-
         /* free waittable in each zone */
         for (i = 0; i < MAX_NR_ZONES; i++) {
                 struct zone *zone = pgdat->node_zones + i;